Massive Galaxies Formed When Universe Was Young, New Findings Suggest

[Elmore Furth]

The early bird catches the worm or in this case catches our attention.

Some of the universe's most massive galaxies may have formed billions of years earlier than current scientific models predict, according to surprising new research led by Tufts University.

"We have found a relatively large number of very massive, highly luminous galaxies that existed almost 12 billion years ago when the universe was still very young, about 1.5 billion years old. These results appear to disagree with the latest predictions from models of galaxy formation and evolution," said Tufts astrophysicist Danilo Marchesini, lead author on the paper and assistant professor of physics and astronomy at the Tufts School of Arts and Sciences. "Current understanding of the physical processes responsible in forming such massive galaxies has difficulty reproducing these observations."

The newly identified galaxies were five to ten times more massive than our own Milky Way. They were among a sample studied at redshift 3≤z<4, when the universe was between 1.5 and 2 billion years old.

The researchers made another surprising discovery: More than 80 percent of these massive galaxies show very high infrared luminosities, which indicate that these galaxies are extremely active and most likely in a phase of intense growth. Massive galaxies in the local universe are instead quiescent and do not form stars at all.

TMassive Galaxies Formed When Universe Was Young, New Findings Suggest
>